docs: def get_swagger_version(obj):
      """ get swagger version from loaded json """
  
      if isinstance(obj, dict):
          if 'swaggerVersion' in obj:
              return obj['swaggerVersion']
          elif 'swagger' in obj:
              return obj['swagger']
          return None
      else:
          # should be an instance of BaseObj
          return obj.swaggerVersion if hasattr(obj, 'swaggerVersion') else obj.swagger